3D modeling the Perrinn Open Source Le Mans LMP1 Racecar - 24 Hrs Le Mans 2018 [#3]

This time it's less text and more pics of progress. Will try to upload a video tonight of the car at the Nurb GT track and Spa and possibly Silverstone.

The Wheels

My initial wheel design for the rear. Here with wireframe:

And the front much narrower:

As it turns out this was actually a mistake on my part. The wheels on Le Mans Prototype 1 class cars are all the same size and width. Only the offset on the rear wheels is different and much deeper.

So here the correction:

The original super high quality model for the wind tunnel simulation (via CFD calculations) and the downgraded but still very high poly CAD model both sported between 110.000 and 220.000 triangles for the wheels and tires while my design comes out at or below 60.000. Good for optimization and performance in sim.

I modeled the wheel on top of the existing one to avoid inaccuracies.

My wheel is built using a variety of modifiers the software (Blender) offers such as the mirror and especially array which are highly useful in building wheels and tires or any complex round objects. Basically you only built part of the wheel and have the program duplicate and align that part until you get a full wheel:

The array is quite simple as in that it uses the geometry you build and mirrored to get one full spoke of the wheel and then duplicates that part however many iterations are required, in this case it's 11. You then set the array in relation to an empty plain axis which sits in the center of the wheel and acts as point of reference and rotation. You then select the axis and rotate it until the wheel is fully closed up. Like here:

The tires are modeled to within 95% of the originals. The surface will be textured and there might be some baking or bump mapping or material shaders to emulate the surface of a real tire. For now I'm using a mixed shader to get the 'rubber look'.

The Body

The exported Onshape CAD model comes with all objects defined, separated and nicely aligned. I first threw out everything we won't need in sim...quite a bunch of parts that cumulatively make up around 1.5 million triangles.

Leaving us with this, same initial tris count of around 500.000 the goal is to get below 150.000 including everything.

So rebuilding will be based on this new and updated high quality model.

Catch ya next time!